[oc] Re: ATA design

["Richard Herveille" <Richard.Herveille@pie.nl>]

Hi Dani,

> Hi Richard,
>
> Thank you for your fast reply.
>
> > Depends on what your goals are, if you just want to connect a harddisk
using
> > PIO transfers (no UltraDMA or Multi-wordDMA transfers) than a Xilinx
will do
> > fine. In fact all you need are some simple buffers. There are quite some
> > examples in the net howto do this. There is one but, it's not compliant
with
> > the ATA specs., but it works fine, I did it for a project.
> I saw a commercial project for a 68k connected to a spartan II xc2s50,
which may
> be used as a PIO transfer device. All I have done with programmable logic
> is some chip select with a gal16v8 ;-).
> I'm currently working on an own 68k board and a friend maybe would like to
> build a battery loader with this board (6 x PWM output) or I would like to
> connect a harddisk to it. What kind of device would you recommend for
> such simple applications? I saw a free tool on the xilinx homepage. I
tried
> some years ago the atmel integrated development system and it was nothing
worth.
> Can I write some VHDL code with the free tool and compile it to a
downloadable
> bitstream? Even with bigger chips, such as the spartan.

Both Xilinx and Altera provide 'lite' versions of their tools. Both are good
and can be used to do designs for their most popular and, from an amateur
point of view, the most interresting devices. I think Xilinx provides its
own VHDL compiler with their 'lite'-version. I know Altera provides a
full-blown Leonard Spectrum version from exemplar for free with their
'lite'-version. And since Leonardo Spectrum is probably the best
FPGA-compiler tool available, that's a great bargain. There's one catch, it
can generate code for Altera devices only.

The catch for 'lite'-versions:
- Xilinx, you can do designs for devices upto 1M gates
- Altera, no APEX devices (well and some others no-one uses/wants to use),
no Quartus development tools (also no Quartus fitter in Max+Plus II)


> What kind of chips and software do you use?
>

I use mostly Altera and am starting with some Xilinx right now. The reason
for this is that Xilinx devices were just not as good as Altera's. But with
the introduction of Virtex Xilinx made a good come-back.
What software am I using;
- Max+Plus II, Quartus (Altera development tools)
- Aliance Elite version (Xilinx development tools)
- Modelsim by Modeltech (mixed-language simulator) www.model.com
- Leonardo Spectrum by Exemplar (great mixed-language compiler)
www.exemplar.com

> > Currently I am working on a full ATA-3 (and eventually a ATA-5)
compliant
> > core. I almost finished the PIO interface. This is the most important
> > interface since all commands towards the ATA device are tranmitted using
PIO
> > transfers. I can send you what I have sofar if you want to.
> I'm doing my work just for fun, but for example if you want to build a
cheap
> small office server with a PowerPC such an ATA controller would be nice.

Well since it is just for fun: I have attached a schematic (found it on the
net somewhere).
Howto connect an Amiga (yes and 68k) to an IDE harddisk. Have fun....

> I read a article about serial ata. Does your design support this as well.

To be short: NO.
Serial ATA is still no standard, and it is totally different from the
current implementations.

Richard

schem13.gif